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# fr4 Dielectric Constant

32 Threads found on edaboard.com: fr4 Dielectric Constant

## Thickness of FR-4 substrate

Bad idea. 1. u could not get the exact valune of the dielectric constant of fr4 at 33GHz. 2. At 33GHz, loss tangent of fr4 is very large.

## Measuring exact dielectric constant without equipment (after fabrication)

If you are using low cost fr4 (Er~4) in frequency range 10GHz to 20GHz, Er will be all over the values on the same PCB. All the microstrip theories would not apply in this situation. For those microwave frequencies you might need to use high quality laminates (from Rogers, Taconic, etc) with low Er (between 2 and 3)

## how to design a FR4 PCB in the layout of a rectifier circuit in ads

for a rectifier board, you do not normally need s parameters unless it is a directional coupler. or microwave you need to choose something like GETEK or a low loss fr4 which has a slightly lower dielectric constant. If you have no board layout software, EAGLE is free.

## FR4 dielectric constant/ permittivity vs. temperature

fr4 means different things to different manufacturers! The best thing would be to build a structure on the same material you intend to use, and measure it drift over temperature.

## characteristics impedance vs dielectric constant vs frequency

Er is dependent on the dielectric material used (4.3-4.5 average for fr4 based PCBs. Z0 is dependent on the topology used on a PCB design, number of layers proximity to planes etc etc. Download and play with this:

## substrate height of patch antenna

If the height is small relative to wave length, you can calculate an effective height for the layered dielectricum. e.g. H(eff) = H(fr4)/4.4 + H(airgap)

## Microstrip patch antenna

Hello Colleague, - I found an accurate equation for Zc in the book "Antennas for all applications" by John D. Kraus: Zc= Zo/(√ε r[(W⁄t)+2) 92593 Where: Zc= Characteristic Impedance Zo = Intrinsic impedance = 377Ω ε r = dielectric constant from your material: I guess is fr4. W = widt

## Why the measure results are not the same by cable and pcb diff_feed

PCB dielectric Coefficient for fr4 is not constant by frequency so that the manufacturers give this coeffcient for certain frequency,temperature and relative humidity.Therefore the dielectric coeffcient which you used to calculate characteristic impedance for PCB traces migh not be correct. In additional to, if the operating (...)

## Substrate thickness problem in patch antenna

I suggest you use GE fr4 called GETEK which has 10x lower loss tangent than most fr4. W I suspect you are using lossy fr4 and also dielectric constants is much lower at 2Ghz since rated parameter . Also dielectric constant drops 10~20% as f goes up. Return loss of thinner (...)

## Dielectric Constant of FR4 at 13.56 mhz

I am making a pcb antenna which has a resonant frequency at 13.56 mhz and which will be etched onto a fr4 substrate These 13MHz "antennas" on PCB are more or less inductors, with inductive near field coupling. They are designed/calculated like other printed regular inductors, and the dielectric constant of the PCB

## microstrip single patch antenna bandwidth improvement

Hi, I am designing a single rectangular patch antenna . the substrate is fr4 and its dielectric constant is 4.4. I have used Inset feed for the antenna. The frequency is 2.4Ghz. I obtained the following results. My resonant frequency(Rf) is 2.399Ghz return loss @ Rf is 40 db There are many ways to choose the Bandwidth . I (...)

## Specifications of FR4 Epoxy.

Hi , I would like to know what are the fr4 PCB's available in the market with permittivity & height. Please let me know lower,higher value of both. thanks a lot

## Electrical length while designing a klofenstein taper

Given your physical length of 77.8 mm and effective dielectric constant of 3.27 (did you use fr4 with er = 4.4?), I would expect the electrical length to be in the range: electrical length = 77.8mm*sqrt(3.27) = 141 mm (above the cut-off frequency). This equals a delay of about 338 degrees at 2 GHz. It will be somewhat more because of (...)

## can we determine dielectric constant of material practically

You see, fr4 isnt a standard thing! Its only a type of material & with an +/- εr value (eventually +/- 20%!) by all vendors.... You have to ask everytimes by impedance critical (PCB) designs your source_or PCB producer_ for the especially used/ possible exact Er-values. Typicall has εr a range of 4.4...4.8 :-) / :-(. K.

## Stiff PCB material with similar dielectric constant as FR4

Hi all, My 1 mm fr4 board warps all over the place when heated. Do u know of a cheap PCB substrate with similar dielectric constant to fr4 but is stiffer? Thanks You have to compromise either on the price or the quality. Naturally you cant expect sugar at price of salt. :D Cheers

## fr4 dielectric constant

Hello vpmedina I think that dielectric constant of a laminate is independent of its thickness. But about fr4, it's produced by various companies in the world. You can find them by googling web, then you can find dielectric constant of their laminates in the datasheets. But as a rough approximation you can (...)

## esign a 4 element patch antenna array

hi there, i need to design a 4 element patch antenna array. i have 6inches (w) by 4inches(h) fr4 board. i need to design the array so that feed network, array and impedeance transformer all fit on the stated board can someone please 1)suggest an appropriate operating frequency for the array 2)tell me the dielectric constant, loss tangent (...)

## multilayer PCB with high dielectric constant

You could probably bond ONE layer of flexible er=10 board on top of a sandwich of standard fr4 boards. I have successfully done that with standard "duroid" type boards at lower er's. Need a processing house that can get the thru holes right! Rich

## Need to get 4- layer PCB fabricated which has RF chip 2.4GHz

Depending upon your circuit if only transmission lines are there then fr4 is good it has a dielectric constant of 4.4. RT duroid is much much better but costly. You can simulate the results with both materials and can see the difference which is better for you circuit. Hope it helps

## What to consider when designing a PCB for RF circuits?

If you're looking for a check list, here's a basic one: 1) Make sure you know the dielectric constant of the board. If you use fr4, and are really high frequency (say 4 GHz) or higher, you may need to design for losses along traces. This is because the dielectric constant of fr4 is only (...)